In

nothing we experience can be absolutely forgotten. real life, in spite of occasional surprises, most of what happens actually is forgotten. The only reasons for supposing that if the conditions were forthcoming everything would revive are of a transcendental sort. Sir Wm. Hamilton quotes and adopts them from the German writer Schmid. Knowledge being a 'spontaneous self-energy' on the part of the mind,

"this energy being once determined, it is natural that it should persist, until again annihilated by other causes. This [annihilation] would be the case, were the mind merely passive. . But the mental activity,

the act of knowledge, of which I now speak, is more than this; it is an energy of the self-active power of a subject one and indivisible: consequently a part of the ego must be detached or annihilated, if a cognition once existent be again extinguished. Hence it is that the problem most difficult of solution is not, how a mental activity endures, but how it ever vanishes." *

Those whom such an argument persuades may be left happy with their belief. Other positive argument there is none, none certainly of a physiological sort.†

When memory begins to decay, proper names are what go first, and at all times proper names are harder to recollect than those of general properties and classes of things.

This seems due to the fact that common qualities and names have contracted an infinitely greater number of associations in our mind than the names of mest of the persons whom we know. Their memory is better organized. Proper names as well organized as those of our family and friends are recollected as well as those of any other objects. Organization' means numerous associations; and the more numerous the associations, the greater the number of paths of recall. For the same reason adjectives, conjunctions, prepositions, and the cardinal verbs, those words, in short, which form the grammatical framework of all our speech, are the

† Cf. on this point J. Delbœuf, Le Sommeil et les Rêves (1885), p 119 .; R. Verdou, Forgetfulness, in Mind, II. 437.

Cf. A. Maury, Le Sommeil et les Rêves, p. 442.

very last to decay. Kussmaul* makes the following acute remark on this subject:

"The concreter a conception is, the sooner is its name forgotten. This is because our ideas of persons and things are less strongly bound up with their names than with such abstractions as their business, their circumstances, their qualities. We easily can imagine persons and things without their names, the sensorial image of them being more important than that other symbolic image, their name. Abstract conceptions, on the other hand, are only acquired by means of the words which alone serve to confer stability upon them. This is why verbs, adjectives, pronouns, and still more adverbs, prepositions, and conjunctions are more intimately connected with our thinking than are substantives."

The disease called Aphasia, of which a little was said in Chapter II, has let in a flood of light on the phenomenon of Memory, by showing the number of ways in which the use of a given object, like a word, may be lost by the mind. We may lose our acoustic idea or our articulatory idea of it; neither without the other will give us proper command of the word. And if we have both, but have lost the paths of association between the brain-centres which support the two, we are in as bad a plight. 'Ataxic' and ‘amnesic' aphasia, 'word-deafness,' and 'associative aphasia' are all practical losses of word-memory. We have thus, as M. Ribot says, not memory so much as memories.† The visual, the tactile, the muscular, the auditory memory may all vary independently of each other in the same individual; and different individuals may have them developed in different degrees. As a rule, a man's memory is good in the departments in which his interest is strong; but those departments are apt to be those in which his discriminative sensibility is high. A man with a bad ear is not likely to have practically a good musical memory, or a purblind person to remember visual appearances well. In a later chapter we shall see illustrations of the differences in men's imagining power. It is obvious that the machinery of memory must be largely determined thereby.

*Störungen der Sprache, quoted by Ribot, Les Maladies de la M., p. 133. + Op. cit. chap. III.

"Those who have a good memory for figures are in general those who know best how to handle them, that is, those who are most familiar

Mr. Galton, in his work on English Men of Science,* has given a very interesting collation of cases showing individual variations in the type of memory, where it is strong. Some have it verbal. Others have it good for facts and figures, others for form. Most say that what is to be remembered must first be rationally conceived and assimilated. +

There is an interesting fact connected with remember ing, which, so far as I know, Mr. R. Verdon was the first writer expressly to call attention to. We can set our memory as it were to retain things for a certain time, and then let them depart.

"Individuals often remember clearly and well up to the time when they have to use their knowledge, and then, when it is no longer required, there follows a rapid and extensive decay of the traces. Many schoolboys forget their lessons after they have said them, many barristers forget details got up for a particular case. Thus a boy learns thirty lines of Homer, says them perfectly, and then forgets them so that he could not say five consecutive lines the next morning, and a barrister may be one week learned in the mysteries of making cog-wheels, but in the next he may be well acquainted with the anatomy of the ribs instead." +

The rationale of this fact is obscure; and the existence of it ought to make us feel how truly subtle are the nervous processes which memory involves. Mr. Verdon adds that

"When the use of a record is withdrawn, and attention withdrawn from it, and we think no more about it, we know that we experience a feeling of relief, and we may thus conclude that energy is in some way liberated. If the . . . attention is not withdrawn, so that we keep the record in mind, we know that this feeling of relief does not take place. . . . Also we are well aware, not only that after this feeling of relief takes place, the record does not seem so well conserved as before, but that we have real difficulty in attempting to remember it."

This shows that we are not as entirely unconscious of a topic as we think, during the time in which we seem to be merely retaining it subject to recall.

with their relations to each other and to things" (A. Maury, Le Sommeil et les Rêves, p. 443)

* Pp. 107-121.

For other examples see Hamilton's Lectures, II. 219, and A. Huber Das Gedächtniss, p. 36 ff.

Mind, K. 449.

"Practically," says Mr. Verdon, "we sometimes keep a matter in hand not exactly by attending to it, but by keeping our attention referred to something connected with it from time to time. Translating this into the language of physiology, we mean that by referring attention to a part within, or closely connected with, the system of traces [paths] required to be remembered, we keep it well fed, so that the traces are preserved with the utmost delicacy."

This is perhaps as near as we can get to an explanation. Setting the mind to remember a thing involves a continual minimal irradiation of excitement into paths which lead thereto, involves the continued presence of the thing in the fringe' of our consciousness. Letting the thing go involves withdrawal of the irradiation, unconsciousness of the thing, and, after a time, obliteration of the paths.

2

A curious peculiarity of our memory is that things are impressed better by active than by passive repetition. I mean that in learning by heart (for example), when we aimost know the piece, it pays better to wait and recollect by an effort from within, than to look at the book again. If we recover the words in the former way, we shall probably know them the next time; if in the latter way, we shall very likely need the book once more. The learning by heart means the formation of paths from a former set to a later set of cerebral word-processes: call 1 and 2 in the diagram the processes in question; then when we remember by inward effort, the path is formed by discharge from 1 to 2, just as it will afterwards be used. But when we excite 2 by the eye, although the path 1-2 doubtless is then shot through also, the phenomenon which we are discussing shows that the direct discharge from 1 into 2, unaided by the eyes, ploughs the deeper and more permanent groove. There is, moreover, a greater amount of tension accumulated in the brain before the discharge from 1 to 2, when the latter takes place unaided by the eye. This is proved by the general feeling of strain in the effort to remember 2; and this

FIG. 46.

Speech

also ought to make the discharge more violent and the path more deep. A similar reason doubtless accounts for the familiar fact that we remember our own theories, our own discoveries, combinations, inventions, in short whatever 'ideas' originate in our own brain, a thousand times better than exactly similar things which are communicated to us from without.

A word, in closing, about the metaphysics involved in remembering. According to the assumptions of this book, thoughts accompany the brain's workings, and those thoughts are cognitive of realities. The whole relation is one which we can only write down empirically, confessing that no glimmer of explanation of it is yet in sight. That brains should give rise to a knowing consciousness at all, this is the one mystery which returns, no matter of what sort the consciousness and of what sort the knowledge may be. Sensations, aware of mere qualities, involve the mystery as much as thoughts, aware of complex systems, involve it. To the platonizing tradition in philosophy, however, this is not so. Sensational consciousness is something quasi-material, hardly cognitive, which one need not much wonder at. Relating consciousness is quite the reverse, and the mystery of it is unspeakable. Professor Ladd, for example, in his usually excellent book,* after well showing the matter-of-fact dependence of retention and reproduction on brain-paths, says:

"In the study of perception psycho-physics can do much towards a scientific explanation. It can tell what qualities of stimuli produce certain qualities of sensations; it can suggest a principle relating the quantity of the stimuli to the intensity of the sensation; it can invesgate the laws under which, by combined action of various excitations, the sensations are combined [?] into presentations of sense; it can show how the time-relations of the sensations and percepts in consciousness correspond to the objective relations in time of the stimulations. But for that spiritual activity which actually puts together in consciousness the sensations, it cannot even suggest the beginning of a physical explanation. Moreover, no cerebral process can be conceived of, which --in case it were known to exist-could possibly be regarded as a fitting basis for this unifying actus of mind. Thus also, and even more emphatically, must we insist upon the complete inability of physiology to * Physiological Psychology, pt. II. chap. x. § 23.